The ozone and temperature measurements by the three atmospheric physics instruments GOMOS, MIPAS and SCIAMACHY aboard the ENVISAT satellite are being compared with the measurements performed with the Brewer 16 spectrophotometer and the ozone-and radiosoundings at the Royal Meteorological Institute of Belgium. Regarding the SCIAMACHY total ozone values, there is a negative bias of about -5% compared to our Brewer measurements.There was no possibility to study the influence of clouds or solar zenith angle. The importance of the distance of the SCIAMACHY pixel from our stations is shown. The GOMOS ozone profiles have been compared to our ozone soundings, but due to the poor quality of the GOMOS profiles measured during daytime, the comparison is made in a qualitative way. For the temperature measurements, there was more co-located data available using radiosondes. The GOMOS low resolution temperature profiles compare very well with the radiosonde profiles. However, from the data it was not clear which values were actually retrieved and which values were taken from a climatology. The MIPAS temperature measurements have been analyzed as a function of distance, pressure level and time of measurement. The general agreement with the radiosonde data is within 2%. There is an indication of a dependency on the altitude when using nighttime data which has to be confirmed when a larger dataset becomes available.